Basin or graving dry dock



Sept. ll, 1945. F. RHARRIS 2,384,616

BASIN QR GRAVINGv DRY DocK Original Flevd March 6, 1943 2 Sheets-Sheet l fsk .IX/ Q-' J.- Lil/I .551 Jal Il# Lf. fg I4 l NVENTOR Sept 11, 15245- F. R. HARRIS -`2,384,616

BASIN OR GRAVING DRY DOCK Original Filed March 6, 1943 2 Sheets-Sheet 2 IN VEN TOR. Pne/v'c' Harris Patented Sept. 11, 1945 BASIN R GRAVING DRY DOCK Frederic R. Harris, New York, N. Y.

Original application March 6, 1943, Serial No. 478,274. Divided and this application October 14, 1943, Serial No. 506,135

14 Claims.

This invention relates to concrete dry docks of the tremie-built type; and especially to the forms or molds into which the concrete is poured during the construction thereof.

This application is a division of my application Serial No. 478,274 for a Graving or basin dry dock, filed March 6, 1943.

The principle of this invention is particularly useful when the concrete is laid and allowed to set under water. My chief object is to provide a means for building a concrete dock with safety, to shorten the time required and reduce the cost thereof.

In practice, wet, plastic concrete is laid by tremie on the bottom of the excavation for the dock, without first unwatering the site, and the deposit of the concrete is controlled and conned, to prevent damage or dilution, and reinforced. Hence, as the concrete hardens, the reinforcements are permanently embedded in it and united to it. The various parts then take shape and the dock can be completed at a great saving in time and cost. When finished it will have all the dependability, stability and security sisted and the foundations of the dock are in no way damaged.

A more particular object is to ensure the best possible joint or union between the walls and bottom so that outside leakage into the dock will be prevented.

The ensuing description sets forth the invention in detail, but alterations of structure may, of course, be made without departing from the underlying principle.

On the drawings:

Figure 1 is a top view showing a construction employed in the rst step of building a dock according to this invention.

Figure 2 is a side View illustrating further the mode of proceeding.

Figure 3 is a top plan view showing in part the appearance of the finished mold forms in position.

Figure 4 shows another modication of my invention relating te the formation of the bottom slab and walls of the dock in cross-section.

Figure 5 is a plan of the construction of the side Walls.

Figure 6 is a top view presenting the same method followed in constructing the inner or head end wall of the dock.

Figure 7 shows this method utilized in the construction of the gate end.

Figure 8 shows a portion of part of the frame-l work used with this embodiment of my invention.

Figure 9 is a cross-sectional view thereof; taken on line 9 9 in Figure 6.

Figures 10, 11 and 12 present structural details.

The same numerals of reference'identify the same parts on all views. v f Y In Figure 2, the excavation for the dock is indicated at F, and on the bottom of it the concrete slab B is laid. The slab is shown iinished at the left only, but it of course extends over substantially the full width of the bottom. The right half of this gure shows in side elevation part of one of the tremie mold forms for the bottom slab, with reinforcing members put into the excavation before the concrete. These forms 3 are laid side by side, but with spaces between them, as illustrated in Figure 3. With the forms and spaces filled with concrete, a continuous layer of concrete of the same thickness as the depth of the forms extends from one end of the dock to the other, The excavation is madeby digging or dredging, to the required depth over the selected area. Water collecting in this pit, even to the point of lling the same, as shown at W, need not be removed when the concrete is poured.

For anchoring the bottom slab down, piles I, made preferably of flanged steel beams of suitable length, are rst forced into the subsoil at the bottom of the excavation to a suilcient depth. These become embedded in the bottom slab B at their upper ends when the concrete sets, and are partially relied upon to resist the lifting of the dock by hydrostatic pressure in the soil when the surface Water in the excavation is at last pumped out. A layer of stone or gravel 2 is also put down on the bottom, and when this layer and the piles are in position, the piles l project about three feet above the layer. Sometimes the dock may have to be designed Wholly without reliance on the piles I, as a precaution against the possibility that the piles might not give any anchoring effect. In such a case, the piles might even be omitted.

Because of water in the soil as above described, there is great upward or lifting pressure against the bottom of the dock. The retention of the water in the excavation at full depth balances this pressure. VBut with the water in the excavar concrete under water by the use of tremie or l pouring equipment, and simultaneously reinforce it; so that, as the concrete hardens, great strength and reinforcing effect are developed.

'I'he tremie forms 3 are fully completed before placing them. They are lowered into the water and come to rest crosswise of the excavation upon the stone or gravel 2. The forms have a Width of 12 to 15 feet; and are as deep as the thickness of the slab B; and they have the shape of closed troughs or pockets, the ends and sides of which are provided by the reinforcing material to 'be combined with the concrete. The piles I project up into the forms and spaces between them. In these molds and spaces between, the concrete can be poured without suffering damage before it sets; and in hardening, the concrete becomes so bonded to the reinforcing material that both are strengthened and stiifened greatly.

As illustrated separately in Figure 2, the bottom mold forms consist of steel side plates 4, with transverse or vertical corrugations, steel trusses 5 and corrugated metal end plates 6, with similar corrugations. The sides 4 may be relatively thin and flexible but are stiffened by trusses 5. Each truss includes two or more longitudinal beams 1, rigid with the sides along the outer faces thereof, and connected by vertical struts 8 and diagonal struts 9. Each truss is light but very strong, and all parts of the form are secured to one another by welding or otherwise. To the end plates 6 are fixed outside strips or battens I0. The end plates 6 are joined to the plates 4 and trusses 5 at the extremities of the latter, Vbut project sideways beyond them. The battens reinforce and stiffen the plates 6. Preferably the beams 1. are angle-shaped in cross section with vertical flanges secured to the plates 4, and turned upward. These bottom forms are light, but strong, and a minimum of steel is employed in making them.

The walls of the dock can be erected on the upper surface of the bottom slab, near its edges, or upon the bottom of the excavation `and around the edges of the bottom slab, and of course becomes virtually integral therewith. An example of the first method is illustrated in Figures 2 and 3.

Previous to putting the tremie forms down into the dock excavation with this method, frames for bracing sheet piling and for reinforcing the dock walls are mounted on the tremie bottom forms 3. The walls are reared against theY inner face of such piling. The frames consist kof uprights II,

yond the sides to such an extent that when the forms 3 are all down and the plates 6 at each end all in line, spaces I4, closed on all four sides, lie between the forms 3, and provide additional forms of slightly less width than the forms 3, as plainly appears in Figure 3. The four frames then rising from the ends of each form 3 may be entirely submerged, with their tops under the surface of the water W. But straight pieces of timber or metal I5, or other suitable members of sufficient height, may be detachably secured to the tops of therframes to project above the Water and serve as markers to show the positions of the tremie forms and frames; and thus facilitate correct alignment when the forms come to rest on the gravel 2. Of course, underwater equipment and even the services of divers could be used for this purpose if necessary.

Next, the sheet piling I5 is set up around the four sides of the area supporting the tremie forms 3 and I4, and encloses a space from which the water can be pumped out when the bottom slab has hardened. For the piling along the sides, horizontal wales or stringers I'I are attached to the outer sides of the aligned A-frames, being bolted, welded or otherwise secured in position; a wale I'I being affixed to each pair of A-frames at the ends of the forms 3, projecting out sideways as far as the end plates 6 and strips Ill; and is lowered into the water with the remainder of the structure. All the wales are in straight alignment when the forms and frames are on the bottom of the dock excavation.

This piling may be made up, for example, of members of the kind described in my Patent No. 1,937,738, covering Sheet piling, granted December 5, 1933, jointed or interlocked along their vertical longitudinal edges. They are preferably provided with hooks IB on their faces. The Wales I'I have upturned flanges with which the hooks engage. At their lower ends some of the piling members will lit into recesses I9 in the side plates 4 of the forms; and thus the whole extent of 'f sheet piling at each side will be kept in place.

The piling is put up so as to be set back a bit from the ends of the forms 3 and I4 for a purpose to be mentioned later.

Similar frames and piling are erected along the two ends of the dock. This construction is fully set forth in my prior application aforesaid, and need not be described at length here, as it is not a part of the present invention.

Concrete is poured in through pipes of sufficient diameter held with their ends relatively close to the bottom of the forms in the excavation, while through these pipes the concrete is poured till the forms 3 and spaces I4 are filled to their tops. One of these pipes is shown at 22 in Figure 2, but several will be simultaneously employed to fill each form at a number of points between the end plates 6; and one or more forms may be filled together. First the tremie forms 3 are filled and then the intervening spaces I4. The center forms may be taken first, and the pipes shifted towards the forms at the ends. Any suitable means for connecting, supporting, and moving the pouring pipes 22 may be employed. As the concrete rises in the forms or troughs 3, 4the vertical grooves in the corrugations of the metal plates 4 and E are occupied by it. The subsequent filling of the spaces I4 covers the trusses 5, and the concreteembeds all of the metal parts. The various blocks or sections in the forms 3 and spaces I4 become rigidly connected to all the metal work, and immovably joined together. The final result is a continuous monolithic stratum of concrete as thick as necessary, fully reinforced crosswise, and well calculated to resist bending moments due to either pressure underneath, or the weight of a ship on top; Due to the closeness of the joint between the concrete and the metal, because of the recessed surfaces aiorded by vertical corrugations of the plates 4 and 6, a great reinforcing effect is assured. Hence, the plates and trusses can even be comparatively light in size and weight. The trusses and plates are, therefore, easy to make up, and move into position, and the tremie forms, 'each of which constitutes a separate reinforcing member, can be readily constructed and at relatively low cost. No large concrete bodies or units have to be first made and then sunk into position.

When the pouring of the concretev into the forms is finished it engagesthe lower ends of the A-frames and piling l S'and secures them in' place as it sets.

In the plates 4 and 6 the vertical corrugations greatly increase the surface of adhesion and'produce a most efficient union between theconcrete and the metal. Even if the concrete did not fully bond with the metal under water, the concrete after hardening assumes along the'sides and ends of the forms, ridges and grooves and other recesses corresponding to the corrugations in'the metal plates 4 and other parts. When both the forms3 and intervening spacesl4 are lfilled 'and the concrete sets, tlie plates 4 and 6 and 'the trusses 5 are tightly embedded in the bottom and the latter receives all the strength and ruggedness which could be desired.

After the pouring of the 'concrete .is thus completed and hardened, v earth or back lll is dumped against the sheet piling along'the two sides and at the head end". It is heaped on the shoulders 21 of the bottom slab B, outside ofthe piling and assists in holding the'bottom slab in place against upward pressure under it.

When the dock is emptied of Water, the weight and strength of the bottom slab, the Weightand pressure of thev earth on the' shoulders 2l' and against the piling I6 and the eifect'of the piles I, are sufcient to resist any upward pressure on the bottom of the dock. The bottom with its embedded reinforcements has sufficient beam strength to withstand the weight of a ship; and, `When not in use, toresist 'effectively any water pressure beneath and to ofset'this pressurev by its own weight and the weight of the walls at the sides and ends, when the walls are added.

A further account of Vthe construction of a dry dock by this method is not needed here, but this type of dock will assist in explaining the structures ofthe remaining views which present the embodiment of the Ainvention which the claims herein recite.

A dry dock built as outlined above, with the walls erected on thetop face of the bottom slab, gives a horizontal joint between the slab and the walls. `Such a joint or seam in a large,'deep dock may allow leakage'of water into the dock and require special measures to prevent it'.` A more efficient and durable union can be produced by connecting the opposite ends of the blocks in the tremie bottom forms to the inner sides of the Walls by starting the walls at the vbottom of the excavation, asindicated on Figures 4 to l2 inclusive. Both the'bottom and the .Walls are then poured under water.

These views, and particularly Figure 4, indicate that the bottom slab B is of a width'no greater than the distance between the -'side wallsl along their inner faces, except as will laterv appear, along the entrance end- The transverseconcretev sections or blocks b of the bottomslab terminate at plates 46. having inclined shoulders 4l. The concrete at the two ends of the bottom slab sections or blocks and in'the lower` portions of the side Walls hardensv against the' plates 46. Thus, in effect, a We'dging joint is made. 'Underground pressure exerted upward on the bottom slab will now hold the ends of the blocks-b more forcibly against these shoulders 4'I and the seal there will be very tight. A similar result is obb tained at the head end ofthe dock,

To this end, tremie bottomforms j are constructed with corrugated side plates stiifene'dfby trusses 5, and end plates 6; projecting as before (see Figure 1) the same distance beyond'theside plates. The plates 46 are aflixed to these bottom forms between the side plates and within the end plates 6. 'The plates 46 make `transverse partitions in the forms, and the trusses 5 extend beyond said plates. The partitions llt areas long as the end plates 6 and project beyond the sidesof the bottom forms as far 'as these plates 6 and battens I0. These partitions maybe'prepared in one piece or in parts, welded'or'otherwise secured to the innerI and outer sides ofthe trusses and side plates to make in'effect a single plate of the same length as the end plates 6. The bottom tremie forms are shown mostly'inoutline on Figures 5', 6 and 7, but are constructed' essen`- tially the same'as'presented in Figures 1,"2 and3, with the partitions 46 added and-th A`frames omitted. Some of them,'further, have'no corrugated plating along part of one'side between the partitions 46 and end plates 6." l t Each bottom tremie form 'also has ''atvhoi- Zontal plates or seats 48 on the' top; for'exanple, oneat each corner on the ends and two adjacent the plate 46, to support upright beams or columns 49 which'hold the tremie concrete mold forms for the vvall sections;v These sections are put up by pouring 'concrete' into `the wall forms Without unwatering the excavation. Each wall section along most of tlie'length'of thesides will be as long as the width of three bottom tremie forms.v (See Figure 5.)' t

The wall vforms for the's'ide walls are indicated at 5U, alternating with Wall forms 5|. The forin- Ver will cover the ends lof two bottom tremiev forms and one space I4 between them. 'The {ithe'rs cover the ends of y one bottoni tremie form and part of the width of an intervening space at each side. The wall formsV 5I] Awill have` vfour sides.

The wall forms 5I each willhave'two sides'onl'y, extending across the bottom forms'. This arrangement is utilized along each sidewall of the dock from the head end to a point near'th'e'entrance. Y 1

As shown in Figure 5, each wall form '50 may be considered as adapted to cooperate withtwo bottom tremie forms, marked 3a, and the space I4 between them. Each wall form 5I stands upon a similar form 3b, which-has similar spaces I4 between it and the forms on both sides. "Several wall forms 50 yand 5I may be needed alongzeach side of the-dock. 'Each row of wall' forms-will start with a wall form similar to that marked-5I nearv the entrance end and terminate with a wall form 5I at the opposite lend as shown in Figures 7 and 6 respectively. The ends of the-bottom forms will be designed so as to cooperate'with the wall forms fully whenl the wall section concrete'is poured in.vr n' u "f As in' Figure' 5, the two adjacent bottom forms la to be considered are shown at the'left. Their end plates 6 are in alignment and so are their partitions 46.v A wall form 50, of metal plating with vertical corrugations, assembled on land and made rigid with bracing, is lowered into piace so that it'will come to rest with the plating of one long side in the same verticalk plane asv the upper portions of thepartitions 46, andthe plating of its opposite long side'in the plane of the end plates 6, of the two trexnie bottom forms 3a. (See Figure 8.) Its plating at the ends will be in the planes of the corrugated side plates 4, of the bottom forms; but the plating of the long sides of the wall form will project beyond the cross-.plating at its ends to the same distance as the'plates 6 and partitions 46 project from the sides of the two tremie forms Zia. The outside vertical beams 46 are adjacent the transverse end plating 6 of each wall form 50; and horizontal wales 52 are welded to the columns 49 and to the outer faces of each wall form l5I). `The wall forms thus can vbe easily hoisted and lowered. The internal bracing of each wall form shown diagrammatically at 56a and 50h, can be of any design suiiicient to serve my purpose; and need not here be set forth in detail.

The mold forms 3a have `the corrugated plates 4 along theirY adjacent or oppOsed sides, which delineate the spaces I4, terminating at the partitions or plates 46. This construction is indicated in Figure 8, which is a view of the end of the form la at the extreme left of-Figure 5, viewed fromthe left. The side plate 4 in line with the cross-plating at the adjacent end ofthe Wall form 56 (the left end of Figure 5) is illustratedY as eX- tending past the partition or plate 46 to the end plate 6; vbut is broken away to show no side plating between said partition and end plate on the opposite side of this form 3a. On the remaining or far side of the other form 3a, there is plating 4 between the plates 6 and 46. This design is clearly indicated atjthe right of Figure 5, which shows the sides of the two forms 3a in line with the cross-plating at. the ends of the next wall form 50 in full lines to signify that the plating tremeends of these forms. It is to be understood,v

of course, that the next wall form 50 at the right of Figure 5 is of the same construction as at the left. No side plating lis needed in the bottom forms 3a below the wall forms 50 at points between theends of the latter. Therefore, when the concrete is poured in the forms 3a and forms provided by Spaces I4 between, it iills these forms from the shouldered plates 46 at one end to those at the other. When a wall form50 is poured full of concrete, the latter lls the'entire space at the ends of the three'forrns 3a and I4, under the wall form 56, from the bottom of the excavation up to the top of the wall form. The plates 46 of the forms 3a extending laterally from each of said forms half-way out tor bridge the intervening space I4, like the end plates 6 of the two forms la, are thus entirely embedded.

`The wall forms'SI areof little different type; consisting of metal plating at the two long sides only. They also have outside -columns 149 con v nected by wales 52 to which the corrugated plating is affixed. There will be the necessary bracing between the corrugated plating along the opposite sides. The wall forms 5|, as stated above, cover the endA of one bottom tremie form indicated at 3b on Figure 5, and project about halfway across the adjacent spaces I 4. The plating 4 along both sides of this form 3b runs only out to the shouldered plates 46; and the end plates 6 and shouldered plates 46 of this form project out into the two adjacent spaces I4 to bridge half of these spaces; the end plates 6 and partition plates 46 of the adjacent forms 3a under the wall forms 50 bridging the other half. Only the trusses 5 of the forms 3b run from the plates 46 therein out to the extremities or end plates 6 of said form. The side plating of the two neighboring wall forms 50 extends out, beyond the cross-plating of their ends, about half-way over the two spaces I4 at each side of the bottom form 3b. Thus, each of the wall forms 5I will also contain the concrete for a Wall section long enough to cover three forms or blocks in the bottom, with the aid of the adjacent forms 50.

Wtih this construction the bottom tremie forms can be lled with concrete poured through the pipes 22 (Figure 2) into them'over their entire lengths between the partitions 46. To build a wall section in the wall forms, concrete is poured into the Wall forms until the wall rises from the bottom of the excavation to the top of the wall forms. None of the water in the excavation is pumped out till later.

To bridge the gaps between the plating on the long sides of wall forms 50 and 5|, the side plating is provided on the vertical edges with closures 53, hinged on in any suitable manner. One or more springs 54 normally tends to pull these closures shut. The springs 53 may be long helical springs, aixed at their extremities to the inner faces of the closures and the sides of the wall forms 5I. Cords 55, attached to the closures, pass through eyelets 56 on the wall forms to the top, and hold the closures in the positions shown in Figure 11 when the wall forms are sunk down into position. The cords are then out or released and the springs 54 then pull all the closures 53 shut.

Each tremie form 3a and 3b can be made up as a complete unit, .as before, on the land, with all parts secured rigidly to the trusses 5; the plates 4 extending along the inner sides of the trusses from one partition 46 to the other, in the case of the forms 3b; and continued along one side only out to the end plates `6, in the caseof the forms 3a. The partitions 46 are welded or otherwise fastened in place and so are the end plates 6, as before; and additional corrugated plating 4, will be extended along and be ailixed to the inner face of the trusses between the end plates B and partitions 46 along the one proper side of each form 3a. When the wall forms 50 and 5I are sunk into the water in the excavation, the vertical plating of their longer sides-will be separated in practice by gaps of about six inches. These gaps are bridged by the closure panels 53 above described. The

next wall form 50 is followed by another like the 6 in every dock containing any of these plates. The spaces. between the bottoms of the wall forms and the mold forms of the bottom slab are small and need no closures.

Reference is now made to Figures 6, 9 and l0. Each of the side walls shown in Figure terminates at the head end of the dock in the section set up by means of a wall form 5l spanning a bottom form 3b, as above described. The trernie bottom form at the inner end of the dock beside this form 3b, is indicated on Figure 6 at 3. This terminal form 3 will have corrugated plating Il` along the full length of its outer side; but along` the opposite side, adjacent the form 3b, this plating will be replaced by a shouldered plate .45a ex.

tendingfrom the line of plates 46 in one end Yof the other forms to the line of the same plates in the opposite ends. At its extremities, the plate or partitionlla will be bent at an angle as shown in Figures 9 and 10.l The right-angled endsof this plate 46a will line up with the same plates in the forms 3a and 3b. When the tremie wall4 forms are now rearedover the terminal form 3 under .water and concrete is poured into same, the head end wall can be built up from the bottom of the excavation to the top of the wall forms and makethe same kind of joint between the endwall and the bottom of the dock as is vshown in Figure` 4. The 4plate 46a will be corrugated vonly below the shouldered portion 4l. The terminal form. 3

will comprise trusses along its two sides, madeA rugatons. Vertical struts vor braces 59A may bev extended from thetop portion of the plate 46a downward and be made rigid with the trusses l'.

and braces 58. All the mold forms in fact may be braced across wherever necessary. Flat plates l48 on supports 48 will be secured in place abovetheVr four corners of the form 3. and at suitable points( along the two sides of this form to support the columns 49 of the wall forms. The form 3. may be braced inside in any manner required.

The wall forms for the corners shown at 6B .willconsist of plating forming two long .sides,y and cross-plating at the ends as indicated in Figure 6. The plating at one end will be extended sideways as indicated at 62; and similar plating E3 will project out at the same side; tolineup with the side plates of the adjacent wall forms 5I for the side walls of the dock.` 'I'he plating at the opposite end of this wall formv B away from the corner of the dock will lie in the same planeas transverse corrugated plating 6 put across the extreme end form 3 under all of the wall form ends. This plating 6 will project at one side of.,

the form as far as the side 3b.

The wall forms 6l between the. wall forms 69 need comprise only two long sides of sheet plating similar to the wall forms 5I. Closure members 53 may be included', thoughnot shown in vFigure 6. Each wall form k6l will likewise have columns 49 to support its sides and rest upon the plates or seats 48, as in Figure 9. This construction will be continued over to the opposite side wall .ofY the dock where a wall form 60 will be used at the corner in conjunction with the sidewallform 5I thereat. The wall forr'ns B0 and 6|. too; will .be bracedinsde and concrete .may be. poured into them and the form 3 :from .the bottom of theexlof the adjacent form cavation to the top, without removing any water. Bracing or trusswork indicated at Se and 65 is attached to the tremie form 3 in position to extend towards the form 3b, being rigidly connected to the adjacent truss 5, plate 45a andthe plating ii. This bracing will be embedded in the block which fills the intervening space is, thereby making the inner end of the bottom slab more rigid and immovable, obviating a tendencyof the concrete to cause creeping of the form 3 laway from said block when the end wall is poured. As stated, the bottom slab is laid by pouring `concrete iirst into the various forms 3a between the plates 46; and then intovthe spaces I4; and then the walls are made by iilling the forms at the head end and sides. i

At the opposite or entrance end of the dock, the extremities of the side walls are preferably finished in the dry by enclosing two areas there with sheet piling, and pumping them clear 0i water. At this end, the line of wall forms along each of the sides will also terminate in a structure of the type 5i, placed centrally over a bot- .tom mold form marked 3b. Beyond this there will be two bottom forms 3c and 3c separated by a space I4. Sheet piling ES will be driven into the bottom of the excavation along the side o1" the form Scfl at the left, across the whole Width of the dock. It will be continued across the ends oi' the two bottom iorms 3c and 3c as far'as the first side wall form Sia., and i'rom this point it will be continued across the excavation again to the opposite side.

On the outside or" said wall orm Bla, a rib 66a, (Figure l2) will be welded to the plating and a similar rib 55o' will be on the outer face of the end plate 6 on the end of the form 3b beneath, To these ribs the last member of the sheet piling 66 can be jointed as the pile members are forced down into the subsoil of .the excavation. This piling willenable corrugated plates E to be dispensed with across the ends of Ithe two forms 3c and Scgthese ends being open, with only crosstrusswork or bracing; and will also render unnecessary any side plating for the bottom form 3c alongthe entrance end of the iioor `of the dock. This formLthereiore, will have along its outer side only the trusswork indicated by the dashed vline 5.' Along its opposite side and the yadjacent side of the other form 3c, plating 4 extends up only to the shouldered cross-plates 46,' in the sameposition as the corresponding plates of other forms.V These plates project as illustrated half-wayv out from the opposing or adjacent sides oi the two forms 3c and 3c into the intervening` space I4; while at their other ends they Yterminate flush with .the sides of the forms bearing them. The remaining side of the inner form 3c, has corrugated plating 4 along its full length, past vthe plates 46, out toits extreme ends. This plating 4 bridges the space between the plate 4t and end plate 6 of the adjacent form 3b, both of which are extended out across the full width oi' the intervening space I4. Y Thus the .bottom forms 3c and 3c' can be lled under water by pouring concrete into them between and up to the partitions 46, and then filling thefspaoe t4 between. Then the ends of the forms 3c and 3c and space I4 between them are filled by pouring concrete between the plates 46 and piling 66. The adjacent form 3U and space I4 between it and the form 3c are filled likewise between and up to the cross-plates 46. With all the bottom forms in place in the excavation, from 3clto V3:', all the bottom forms and spaces I4can be poured at the same stage in the construction of the dock. Then the side walls and end walls are put up by pouring concrete in the wall forms 50, l,- la, Gil-and 6i as above described. Each wall form 5la at the entrance end has its inner and outer side walls extended as far as theside of the form 3c, and there connected by end or cross-plating in the vertical plane as the plating 4 of said form 3c. These wall forms- Sla are filled like the others by pouring them full from the bottom of the excavation to their tops.

A line of temporary sheet piling 61 is now erected across the full width of the dock and side walls, and is connected to the piling 66 near the sides of the dock by two lines of temporary piling 68. Thus cofierdams 69 are built at the entrance ends of the side walls, and a large central enclosed space 16. The cofferdams 69 are then pumped out, and the outshore ends of the side walls erected to their full height in the free space thus obtained. These ends will be formed with inside shoulders 1I for the pontoon gate. When they are finished, they receive a lining on their inner` faces. The floorof the bottom between said ends receives a similar lining and the space between the two lines of piling 68 can be pumped out for this purpose.

The tops of the walls are illustrated in Figure 4 at 12. To erect them, the head end wall and side walls up to the piling 61 after the tremie wall forms are filled with the concretefreceive lines of sheet piling 13. These may be attached to the wall forms by bracing 14 and 15, and the lower ends of the pile Amembers are embedded in the concrete. The bracing may be secured in any suitable manner. When the wall forms have been filled and the concrete has set, the dock may be pumped out to lower the water level down a little below the tops of these forms. All the work to make the tops 12 of the walls can then be done above Water. Back fill is finally heaped into the sides of the excavation up to the level of the earth and the columns 49 and plating and piling on the outside faces ofthe walls completely interred. The finish lining 16 similarly embeds and covers the metal work on the inner faces.

The piling 66, 61 and 68 each is as high as the finished walls. The piling 61 extends across the tops of the wall forms Sla, consisting of shorter members there and embedded in the concrete; and it can be jointed to the sides of the piling 13 and to the inner side of the wall form Sla by means such as shown in Figure 12. Between the side walls .the temporary piling l-'ll and 68 are sealed on the floor of the dock by means of troughs put down under the water and in watertight engagement with the floor. The lower ends of the piling are sealed in said troughs. To set the piles 61 and 68 into place, wooden frames are built and sunk down into the Water to brace the piling and facilitate its erection. After the completion of the dock the piling 61 and 68, with framing and other appurtenances, are removed and so is the piling 66 across the entrance end, the remaining piling 66 being covered with earth. The piling 66 and 68 can be taken away first to enable the pontoon gate to be floated into position, the dismantling of the piling 61 then following as the iinal step.

This dock too, can be made narrower at its ends by building the walls so that they converge somewhat, and making the bottom forms of less length away from the middle of the dock.

By lining with plywood the inside of any of the mold forms for the walls oi the dock, a surface can be obtained smooth and finished to such an extent as to make a lining unnecessary.

The tops of the walls 12 have chambers indicated at 11 therein, a roadbed 18 on top forcrane tracks, and a gallery or walk 19 for workmen.

Having described my invention, what I believe to be new and desire to secure. and protect by Letters Patent of the United States is:`

1. A mold form for the bottom of a basin dry dock, having substantially parallel, vertical sides comprising reinforcing members, and vertical transversely extending plates joining saidv sides adjacent the ends thereof, said kplates having.

horizontal shoulders presented outward of the respective ends. Y

2. A mold form for the bottom of a basin dry dock having substantially parallel, vertical sides comprising reinforcing members, one of said sides being a vertical plate having a substantially horizontal shoulder near its upper edge running longitudinally over substantially its entire length, and presented towards the opposite side.

3. A mold form according to claim 2, wherein the plate also has transversely extending, outturned ends, and a horizontal outwardly presented shoulder in each of said ends.

4. The mold form according toclaim 2, where--A in the shouldered plate is vertically corrugatedv between its shouldered portion and its lower edge.

5. In a basin dry dock, a series of mold forms,

arranged end to end along the sides thereof, said forms comprising corrugated plating in line at the inner and outer sides, with gaps between the plating, and releasable closure members hinged to the ends of said plating to span the gaps between the side plating of said forms.

6. In a basin dry dock, a plurality of bottom forms having sides including reinforcing members, elevated seats at the tops of some of said forms, and wall forms. having supporting columns resting uponsaid seats.

7. In a basin dry dock, a bottom mold form having plating along its sides and exterior, pro-` jecting truss-work running continuously Yalong one of said sides,.and beyond the latter.

8. In a basin dry dock, a bottom form having vertical sides and exterior projecting truss-work running continuously.A along one side and wall forms comprising sides and ends, on the ends of the bottom form, said bottom form having plates projecting outward from one side adjacent the ends. of said bottom form, said platesbeing vertical and each having a horizontal shoulder under the inner side of the wall forms and presented outward of the respective ends.

9. In a basin dry dock, the combination oi a pair of forms side by side across the bottom, with spaces between them, said forms each having plates adjacent the ends. projecting outward inw. said spaces to bridge same, and a wallform on each end of said bottom forms, spanning the adjacent sides thereof and projecting beyond said bottom forms over said spaces, said' plates being vertical and each having a horizontal shoulder under the inner side of thev Wall forms. and presented outward of the respective ends.'

10. In a basin dry dock, the combination of a bottom form having shouldered platesat the ends projecting outward at both sideswthereoi, and a wall form on each. end of the bottom form, and projecting over both sides thereof, said plates being vertical andV each having a horizontalA shoulder under the inner 'side of thewall forms and presented outward of the respectiveends.

11. In a basin dry dock, the combination o! a bottom form, having a transversely extended end, a wall form on each extremity of the bottom form and projecting beyond the sides thereof, said Wall form and the end of said bottom form having outside vertical aligned ribs for connection with adjacent sheet piling.

12. In a basin dry dock, the combination of a bottom form and a wall form thereon, said forms having aligned vertical, outside ribs to connect sheet piling thereto, said ribs being at the outer end of the bottom form and outer face of the Wall form.

13. In a basin dry doek, the combination of a 

